The classification and grading criteria of depression can be divided into mild, moderate and severe according to the richness of symptoms and the degree of harm of symptoms to life. The core symptoms of depression include low mood, lack of interest in doing things, energy fatigue, physical exertion, etc., as follows: 1. Mild: Mild depression is accompanied by two or more core symptoms and three of the following concomitant symptoms, including low self-esteem, self-guilt, negative perceptions, abnormal appetite, abnormal libido, weight loss, and anxiety symptoms, autonomic disorder symptoms, etc. Mild depression is accompanied by social function 2.Moderate: There are three core symptoms and four or more concomitant symptoms, and social function is largely impaired, which means that they cannot work and live normally. 3.Severe: If depression is very serious, including three core symptoms and four or more concomitant symptoms, social function is seriously impaired, and they cannot work and live normally, they should consider Severe depression.